Electkio aeg lamp



(No Model.) 4 Sheets-Sheet 1.

J. H. R. WARD. ELECTRIC ARC LAMP.

No. 449,238 Patented Mar. 31, 1891.

(No Model.) 4 Sheets-Sheet 2.

J. H. R. WARD.

ELECTRIC ARC LAMP.

No. 449,238. Patented Mar.31,1891. F 1 J44 J, H; Tit I J! 11 ll I '1 I W|TNEE PL/EATER W 7 W 6, MHZ 711155 Wm M 4 61... wwdw m: News PiYEflS :04, more-Luna, msnmcvon, D c.

(No Model.) 4 Sheets-Sheet 3. l

J. H. R. WARD.

ELEGTRIC ARC LAMP.

No. 449,238. Patented Mar. 31, 1891.

mm figpmav l3) HIS /7T7'0RNEY 7:4: mm Inns (2a., mom-Luna, msumnrou, n. c,

(No Model.) 4 ShpetsSheet 4.

J. H. R. WARD. ELECTRIC ARC LAMP.

No. 449,238. Patented Mar. 31,1891.

BY HA5 flTTORNE) mow-mum, wumao'mu a c UNITED STATES JOHN H. R. XVARD, OF NEW YORK, N. Y., ASSIGNOR TO ARC LAMP COMPANY, OF SAME PLACE.

PATENT OFFICE.

THE UNIVERSAL ELECTRIC-ARC LAM P.

SIECIFICATION forming part of Letters Patent No. 449,238, dated March 31, 1891.

Application filed December 11, 1890 Serial No. 8746M. (No model.)

T0 at whom it may concern:

Be it known that I, JOHN H. R. WARD, a citizen of the United States, and a resident of New York, county and State of New York, have invented certain new and useful Improvements in Electric-Arc-Lamp Compensators, (Case No. 1,) of which the following is a specification.

The invention relates to means for maintaining the arc of the lamp at substantially uniform intensity, especially during the first few minutes or half hour after the lamp has been switched into circuit. The type of lamp to which my invention is especially applicable is that which is used with currents of comparatively low electro-motive force. In these lamps it is usual to employ a resistance-coil in the chimney of the lamp, and as said coil becomes hot the metal portions of the lamp gradually conduct the heat to the operatingmagnet or solenoid of the lamp. Consequently the resistance of the wire of the magnet orsolenoid gradually and slowly increases and does not reach a constant maximum resistance until several minutes after the lamp has been started to burn. A corresponding variation of the light ensues. To overcome this difficulty, 1 construct a lamp as set forth in every detail in the accompanying drawings.

Figure l is a vertical section of the chimney of the lamp, showing the resistance-coil divided into sections. This is the coil referred to afterward as that which causes the whole lamp to become heated. Fig. 2 is a plan view of Fig. 1, with the upper cap removed. Fig. 3 is a vertical elevation of the ribbed tube upon which the resistance-coil is wound. It is not clearly visible in Fig. 1. Its ribs are provided with a heat-insulator to prevent as much as possible any heat from being conducted from the coil to the tube, and hence to the operating-magnet of the lamp. Fig. 4 is a front elevation of a portion of a lamp equipped with my invention, showing the mechanical construction as used in practice. The magnet and German-silver coil are both visible. In these figures the connecting-conductors to different portions of the lamp are shown. Fig. 5 is a diagram view of a modification of the invention whereby the are bepass air for ventilation.

comes adjusted quicker after the lamp is turned on. Figs. 6 and 7 are views of details of Fig. 5, the former being the base-plate of the chimney and the latter the base-plate of the operating-magnet. The German-silver coil is shown dotted. Figs. 8 and 9 are respectively sectional and outside views of the lower portion of the chimney. Fig. 10 shows in diagram the electricaldistribution system and electrical connections in the lamp. Lamps are connected in pairs in parallel, and the intensity of the light is regulated by the coilin the chimney.

(Z represents the upper casting, which is supported upon the pillar e, and which in turn supports the element (1', which is the chimney of the lamp. The casting (1 consists of an inverted hollow cylindrical piece provided with a peculiarly-shaped ventilatingsupport for the chimney. This support consists of a tube 1', provided with ribs or extensions s, radiating from the outer surface of said tube, said ribs being in the shape of steps, the step being represented by .9. Upon these steps (there being one step for each rib) rests the chimney q. Through the spaces between the ribs and below the steps 8 may A similar construction is provided at the upper end of the chimney.

Into the tube 0' screws a smaller tube 0* also provided with ribs or linear projections, which are lettered i. There are six ribs provided. Arc-shaped strips of insulation of fireproof material-such as asbestus 'u-extend along and near the outer edges of said ribs. A subdivided coil of wire of high resistancesuch as a German-silver coil o-is wound upon the asbestus. The ribs and asbestus serve to hold the wire coil at the proper distance from the tube r, while the asbestus itself forms a good fireproof insulation from the metal ribs 2?. The asbestus also forms a convenient bad conductor of heat. On the upper end of the tube r is provided an external screw-thread 7' which carries a cap r provided with ribs s 5 represents steps corresponding to 5. Against these steps presses the upperend of the chimney q, so that the cool air which enters at the lower end of the chimney passes out at the upper end between the ribs 8 The interior of the chimney is lined with a comparatively heavy thickness of asbestus g. This asbestus,beinga poor conductor of heat compared with metal, prevents considerably less heat being conducted away to the magnet of the lamp than if it were-not present.

At the same time it is fire-proof substantially; The ring to forms a part of the same casting with the cap r This is the usual ring employed for suspending the lamp. Between the coil 0 and the asbestus lining q is a cylindrical tubular space afor a passage of some of the air passing through the cylinder.

1 y g 1 1 g are copper conductors connecting the terminals of the several sections of the subdivided coil 1) (see Fig. 2) to the respective terminals of the various electrical devices or parts of the lamp. The wire or conductor-y connects with the binding-post Y. The conductor y connects with the uppermost-binding-post Y. Binding-posts Y Y Y (see Fig.9) are provided and are insulated from each other, and are respectively connected permanently with the conductors m 1 3 The conductor is connected to one of the terminals Y of the lamp, the other terminal being indicatedby Y". The terminals Y and Y are connected to the poles A, respectively, of the generator B. A screw-plug G is adapted to pass through one or the other openings made in the conductor D and to press against any one of the binding-posts Y Y &c. The conductor D is enlarged, as indicated in the lamp by l), which passes through the entire length of the block .2. When the screw-plug C enters holes E in said enlarged portion D, it presses against one or the other of the binding-posts Y Y 850., so that according to the hole in which the screwplug is introduced one or more of the sections of the subdivided coil 1; will be included in circuit with the carbon-holders. The enlarged portion D forms a projection to the terminal Y which is properly insulated by washers F from the casting d. Similar washers P insulate the terminal Y from the casting 'd. The binding-post Y connects by the conductor G with the magnet H. The same terminal is connected by the conductor G with the lower-carbon holder 19. The frame m has a projection m, provided with a hole through which passes the upper-carbon holder 19'. In this circuit is included also the Germansilver coil H This holder is provided with a hole L, so that when the carbon has fallen orhas been fed to approximately its lowest position the brush J ceases contact with the holder, which is in the form of a tube. V In order to effect this cutting out, the brush J is bent outward, as indicated by the bent portion J. The brush J is attached to insulation M, which is mounted upon the pole-piece by atmospheric changes, or to become covered with particlesof dust, which serve gradually to disintegrate the insulation. The brush J'is of such a tension and of such a length that when it arrives opposite the hole L it will not be in contact with the holder 19, so that when the carbon-holder is in its lowest position the magnet H will be cut out of circuit. At any time desirable the carbon-holdersp and p may be cut out of circuit by circuitcontrollers N. (See Fig. 9.)

It was stated above that electrical contact from the frame mto the carbon-holder c was made at the projection m, It is also formed at the projection mithrough which is a hole for thepassage of the carbon-holder p. The holes in the projections m and m are as nearly as possible equal to the diameter of the carbonholder p, while the surfaces of all three ele-' ments are bright, so that the electrical contact is certain.

When the lamp is included in a circuit carrying a current of high eleotro-motive force as compared with another current carrying a lower electro-motive force, the lamp may be adapted to each current by varying the number of sections of the coil 4) in direct circuit. The whole of said coil is always in circuit; but when the screw-plug O is put in contact with the binding-postY forinstance, the uppermost section of the coil becomes a shunt to theother coils, so that the resistance of the lamp becomes less than when the screw-plug C is removed. The resistance may be further descreased by placing said screw-plug successively in'contact with the binding-posts Y Y Y.

The ventilation through the lamp-chimney is a means of maintaining the temperature of the magnet H as low as possible. The object in maintaining or obtaining a small increase of temperature of the magnet 1-1 over the ordinary atmospheric temperature may be stated as follows: As the resistance increases with the heat, the resistance of the wire of the magnet H gradually increases, so that a con-,

siderable length of time passes before the lamp reaches its normal condition. By the mechanical construction of the lamp this interval of time is considerably shortened.

Attention is particularly called to the highresistance coil H permanently in circuit with the magnet H. The coil H is of such diameter and length that the current of the lamp heats it, and thereby causes its resistance to increase. Consequently the resistance of the circuit of the magnet Hincreases almost immediately after the current begins to pass through the lamp. WVithout this German-silver coil the resistance of said circuit would increase only slowly, and therefore the lamp would correspondingly slowly reach the normal candle-power. It is true that the German-silver coil is not an absolute compensator; but when its resistance is about two-thirds that of the magnet H it so fully compensates that the lamp is practically of a given uniform candle-power Within a few seconds after the current is turned on.

In Figs. 4, 5, 6, 7, and 8 is another modification. The degree of compensation of the coil 11 is greatly increased and more perfect. The base-plate c is provided with holes 0' around the lower part of the magnet H, and the upper plate (Z is likewise provided with holes cl in place of the radial projections s. A circular rim or projection d surrounds the holes (1, so that the chimney-casing q will fit therein and prevent water from entering the holes d. The coil II is inclosed entirely by a box or casing a, so that the said coil may get warm as rapidly as possible and to the maximum temperature with a given current, while the ventilating system, by the holes 0' (Z and hot coil o, is intended to maintain the magnet H as cool as possible with a given cur rent. The small arrows show the direction of the draft caused by the suction of the Warm air issuing from the upper part of the chim ney.

I claim as my invention 1. In an electric-arc lamp, the combination, with the regulating resistance-coil and operating-magnet H, of a resistance-coil H in circuit with said coil 2; and magnet H, the resistance of the coil H being substantially two-thirds that of the magnet II.

2. In an electric-arc lamp, the combination, with the regulating resistance-coil and operating-magnet H, of a resistance-coil H in oircuit with said coil 7) and magnet H, the resistance of the coil H being such that it becomes heated more rapidly than the magnet H With a given current.

3. In an electric-arc lamp, the combination, with the regulating resistance-coil and operating-magnet H, of a resistance-coil H in circuit with said coil v and magnet II, the resistance of the coil H being such that it becomes heated more rapidly than the magnet H with a given current, the said coil l-I being inclosed in a box a.

4:. In an electric-arc lamp, the combination, with the regulating resistance-coil and operating-magnet II, of a resistance-coil H in circuit with said coil v and magnet H, the resistance of the coil H being such that it becomes heated more rapidly than the magnet H with a given current, the said coil ll bein'g inclosed in a box a and magnet H being in the path of a draft from the outside air to the chimney of the lamp.

In testimony that I claim the foregoing as my invention I have signed my name, in presof two Witnesses, this 22d day of November,

JOHN H. R. WARD.

Witnesses:

W. A. COURTLAND, EDWARD P. THOMPSON. 

